How do we evaluate patients before epilepsy surgery? Yotin Chinvarun, MD Chaiyos Khongkhatithum, MD How do we evaluate patients before epilepsy surgery? Chaiyos Khongkhatithum, MD Division of Neurology Department of Pediatrics Faculty of Medicine Ramathibodi Hospital Mahidol University 1
Topics Who? Why? How? Outcome: Benefits & Complications Intractable Epilepsy Recurrent unprovoked seizures occur in 1-2% of children 20-40% of children with epilepsy not respond to optimal medical treatment 2
Epilepsy Surgery; Who? Drug resistant epilepsy is defined as Failure of adequate trials of two tolerated, appropriately chosen and used antiepileptic drug schedules (whether as monotherapies or in combination) to achieve sustained seizure freedom When Patients with Epilepsy should be Referred to Neurologist/Epileptologist Doubt in diagnosis Inability to control seizures with appropriate 1-2 anticonvulsants Epileptic encephalopathy: West syndrome, Landau-Kleffner syndrome Hemimegalencephaly, hemispheric cortical dysplasia, Sturge-Weber syndrome (SWS), mesial temporal sclerosis, TSC 3
ทำไมจ งต องผ ำต ด? Epilepsy Surgery; Why? Adverse effect of recurrent seizures on brain development, learning, and memory Psychosocial issue: depression, aggressive behavior, stigma, social isolation, increased utilization of medical services Side effects of anticonvulsants Premature death: SUDEP. 4
Epilepsy Surgery; Why? Increased plasticity of developing brain in children Shorter duration of intractable epilepsy determined better post-operative outcome In large series, there is a delay between onset of epilepsy and presurgical evaluation of ~ 20 years, even when the refractoriness of the epilepsy became clear at an average time of 9 years Berg AT, Neurology. 2003;60:186 190 Long-term Outcomes Hamiwka L. et al 2005 Kloss S. et al 2002 Mittal S. et al 2005 N Years of FU Seizure-free outcome (%) 38 10 Tumors (72) Cortical dysplasia (32) 68 3-10 Cortical dysplasia (50) 109 5-20 Temporal lobe epilepsy (82) 5
Increasing Utilization of Pediatric Epilepsy Surgery Pestana Knight E., Epilepsia. 2015;56:375 381 กำรประเม นก อนกำรผ ำต ด 6
Principles of the Epileptogenic Region (ER) Lüders HO, Epileptic Disord 2006;8 (Suppl. 2):S1-9 Presurgical Evaluation Video EEG monitoring MRI brain Interictal/ictal SPECT Positron emission topography(pet) Magnetic electroencephalography(meg) Dense array EEG EEG-fMRI Functional MRI (fmri) Wada test (intracarotid sodium amobarbital) Neuropsychological tests ER Functional mapping test 7
Epilepsy Monitoring Unit (EMU) Interictal EEG low cost and global accessibility A single discrete focus High reliability of localization: convexity foci False localization: basal, mesial temporal, or interhemispheric foci False lateralization: hemispheric syndromes Localized lesions may demonstrate interictal discharges multifocally at remote/contralateral sites or bilaterally Focal attenuation or bursts of fast activity Jayakar P, Epilepsia 2014;55(4):507 518 8
Ictal EEG with Video Same limitations as the interictal discharges Low amplitude fast activity at seizure onset or deep foci may not be evident on the scalp Confirm seizure semiology Identification of multiple seizure types or nonepileptic events Jayakar P, Epilepsia 2014;55(4):507 518 จำนวนรวมผ ป วยท Admit ห อง EMU รำมำธ บด แต ละป (เร ม 13 ก.ค.52) ป พ.ศ. จำนวน (รำย) 2552 6 2553 35 2554 33 2555 52 2556 51 2557 44 9
Safety Issue Medical complications In pediatric EMU (454 admissions) Falls 1 Symptomatic subdural fluid collection 1 Hip pain 1 Postictal psychosis 1 Epileptic complications Status epilepticus 13 patients 17 events Rescue medications given 35 patients Arrington DK, Epilep & Behav. 2013;27:346 350 Magnetic Resonance Imaging Focal cortical lesion is a reliable marker of the location of the epileptogenic region(er) Smaller or rarely larger than the ER May help restrict the extent of resection Multiple lesions (e.g., tuberous sclerosis or nodular heterotopias) does not necessarily mean that seizures are multifocal onset Standardized high resolution MRI protocol 3T MRI is superior to 1.5T unfavorable time window (6 mo 2 y) 10
MRI Brain: MTS MRI Brain: HT Harmatoma 11
MRI Brain: Ganglioglioma หลอดเล อดผ ดปกต ในสมอง: AVM & Cavernoma 12
MRI Brain ในผ ป วย TSC MRI Brain: Heterotopia & Polymicrogyria 13
Hemimegalencephaly & Sturge-Weber Syndrome Medically refractory, catastrophic epilepsy Focal deficit: hemiparesis Hemisperectomy: plasticity of developing brain SPECT Interictal Ictal ขณะช ก: ม กำรไหลเว ยนของเล อดเพ มข นท สมองด ำนขวำล ำง 14
PET Scan ขณะไม ช ก: ม กำรใช น ำตำลกล โคสลดลงท สมองด ำนขวำทำงด ำนหน ำ Neuropsychology & Neurodevelopmental Testing Baseline data for later comparison to quantify surgical impact and outcome Characterization of cognitive strengths and deficits sometimes not previously detected Informing the risk of postoperative deficits Contribution to the localization/lateralization of function Delineation of specific aims of surgery Information pertinent for educational and rehabilitation planning 15
Diagnostic test utility voting results in major clinical cohorts Jayakar P, Epilepsia 2014;55(4):507 518 Major Indications for the Implantation of Subdural grids 1. Determination of extent and distribution of the epileptogenic zone. Normal imaging data (non-lesional) Epileptogenic zone more widespread than the structural lesion Discordance of non-invasive data Epileptogenic zone relationship with structural lesion Dual pathology 2. Determination of the relationship of the epileptogenic zone to eloquent cortex Cortical stimulation Somatosensory evoked potentials Cortico-cortical evoked potentials Bingaman WE, Bulacio J. Childs Nerv Syst. 2014;30:1897-904 16
Case Demonstration A Thai 13-year-old girl Seizure onset 3 years Seizure Semiology: Abdominal aura Hand and/or oral automatisms Complex motor seizure GTC (rare) Duration~ 2-5 min Frequency: 1-2/week up to daily Current AEDs: Valproate, Topiramate IQ: Slow learner Video EEG moitoring Video recording 17
Ictal EEG MRI brain 18
SPECT Interictal Ictal ขณะช ก: ม กำรไหลเว ยนของเล อดเพ มข นท สมองด ำนขวำล ำง Intractable Epilepsy Video EEG Localization-related Generalized/Symptomatic MRI/SPECT/PET/MEG VNS or CC or KD Lesional with concordant neurophysiology and imaging fmri/wada as needed Neuropsychological assessment Non-lesional or Discordant neurophysiology and imaging or Lesional but near eloquent cortex Invasive EEG Lesionectomy or cortical resection Resection No resection VNS= Vagus nerve stimulation KD= Ketogenic diet VNS or KD 19
กำรผ ำต ดสองข นตอน (Invasive Monitoring) ค ำใช จ ำยส งและใช เวลำมำก 20
ผ ป วยภำยหล งได ร บกำรผ ำต ด Ramathibodi Excellent & Comprehensive Epilepsy Center- RECEC Medicine & Pediatrics Neurosurgery Neuroradiology & Nuclear medicine Psychiatry Neuropathologist Nurses & EEG technicians 21
Ramathibodi Excellent & Comprehensive Epilepsy Center 22